Field of the Invention
The present invention relates to a radiation imaging apparatus, a radiation imaging system, control method of the radiation imaging apparatus, and a non-transitory computer-readable storage medium.
Description of the Related Art
As a radiation imaging apparatus that obtains a radiation image by using radiation (X-rays or the like) transmitted through an object, a radiation imaging apparatus that can display a radiation image in real time has been widely used. In addition, a flat panel type radiation imaging apparatus (FPD) has been proposed.
The FPD detects a radiation irradiation amount during an arbitrary accumulation time as a charge amount. For this reason, if charge irrelevant to irradiation with radiation exists in a radiation detector at the time of obtaining a radiation image of an object, this charge is superimposed as noise on the radiation image. This causes a deterioration in the image quality.
Japanese Patent No. 4557697 has proposed a technique for obtaining offset correction data by determining the stability and variation amount of offset correction data with respect to time, in order to hold the accuracy of offset correction processing for removing an offset component owing to noise accumulated during imaging for a radiation image. U.S. Pat. No. 7,492,865 has proposed a technique for switching between methods of obtaining offset correction data depending on whether to obtain a moving image or still image. Japanese Patent Laid-Open No. 2016-95278 has proposed a technique for reducing temperature fluctuations affecting offset correction processing by always performing the same operation regardless of frame rates.
Although each technique described in Japanese Patent No. 4557697 to Japanese Patent Laid-Open No. 2016-95278 has disclosed the method of obtaining the offset correction data to maintain the accuracy of offset correction processing, a consideration regarding a power supply form has not been made. Therefore, the offset correction data needs to be obtained periodically also in the case of a limited energy supply source such as power supply from a battery, or power is consumed except for an operation needed for imaging in order to reduce the temperature fluctuations, limiting the possible imaging time and the possible number of frames that can be obtained. Thus, in the related art, it is impossible to perform appropriate offset correction considering the form of power supply to the radiation imaging apparatus, impairing user convenience.
The present invention has been made in consideration of the above-described problems. The present invention provides a technique for implementing appropriate offset correction considering the form of power supply to the radiation imaging apparatus.